Conventionally, as for disk players, such as CD, DVD, and MD, or other in-vehicle electronics, etc., the viscous-fluid-sealing damper has been used in order to damp vibration transmitted from outside to a mechanism chassis. An example of such an in-vehicle CD player is shown in FIG. 5. An outer frame chassis 10 shown in FIG. 5 is fixed to a concave portion of a vehicle in which the electronics are housed. A mechanism chassis 11 for supporting a disk rotation drive section and an optical pickup drive system is supported by the outer frame chassis 10 in a floating state through a viscous-fluid-sealing damper 12 and 12 . . . . Subsequently, even if the outer frame chassis 10 vibrates with the vehicle when the vehicle is being driven, vibration of the mechanism chassis 11 is damped, thus enabling to read a CD normally.
An example of such the viscous-fluid-sealing damper is disclosed in Patent Document 1. Namely, the viscous-fluid-sealing damper 12 shown in FIG. 6 is such a damper that a viscous-fluid 14 is encapsulated in a partition wall 13 composed of a bottom surface 13a, a bursiform section 13b, and a shaft receiving section 13c, and most of the bursiform sections 13b and the shaft receiving sections 13c are formed of a rubber elastic body.
This bottom surface 13a is fixed to the outer frame chassis 10, and an installation shaft 3 set up on the mechanism chassis 11 is fitted in the shaft receiving section 13c as shown by an arrow. A swollen head 3b larger than a shaft component 3a in diameter is formed at a tip of the shaft component 3a of the installation shaft 3, and a latching concave portion 13e with large diameter is formed at a tip of an insertion concave portion 13d of the shaft receiving section 13c, and the swollen head 3b of the installation shaft 3 fits into the latching concave portion 13e, so that the installation shaft 3 is fitted in the shaft receiving section 13c. 
Patent Document 1: Japanese Patent Application Laid-Open No. 2004-340378, Paragraphs 0017 to 0032, FIG. 1